Intercontinental Ballistic Missiles

After World War II, the U.S. defensive policy of strategic deterrence depended on a
large fleet of long-range bombers that could deliver accurate nuclear strategic attacks.
This method of defence was too slow to deploy in case of extreme emergency, a better,
faster, and less costly solution was needed.

Three developments in the mid-1950s, however, led to the intercontinental ballistic
missile (ICBM): (1) development of the thermonuclear bomb with a much greater destructive
power than the original atomic bomb; (2) the rapid refinement of inertial guidance systems
for ballistic missiles; and (3) the development of powerful booster engines for multistage
rockets, greatly increasing their size and range. As a result, ballistic missiles became
sufficiently accurate and powerful to destroy targets 8000 km (5000 mi) away. For more
than thirty years, the ICBM has been the the symbol of the United States' strategic
nuclear arsenal.

US / USSR Intercontinental Ballistic Missiles

Atlas D Missile Intercontinental Ballistic Missile stands 75ft high and 10 ft in diameter.
Atlas, the U.S.'s first successful ICBM, was tested in 1959 and was followed one year
later by theTitan. Both were multistage liquid-fueled rockets using extremely low
temperature propellants that had to be added just before launching.

Minuteman I in silo 53 ft high, 5.5 ft in diameter.The U.S. Minuteman II ICBM (second
generation) that went into service in 1962 used solid fuels stored within the missile,
could be launched on short notice, and was sheltered in underground concrete silos. It
could carry three individual warheads.

The U.S. Peacekeeper ICBM (formerly MX), the most modern ICBM used by the United States
during the 1990s. Its design combines advanced technology in fuels, guidance, nozzle
design, and motor construction with protection against the hostile nuclear environment
associated with land-based systems. The Peacekeeper is much larger than Minuteman, over
70 feet long and weighing 198,000 pounds.